Hot melt compositions have heretofore frequently been used as binders or adhesives. One important use of such materials is in the production of melt blown fabrics. Examples of such fabrics and methods for producing the same are set forth, for example, in Anderson et al. U.S. Pat. No. 4,100,324, issued Jul. 11, 1978. As set forth in that disclosure, the thermoplastic polymers preferred for use as binders include polyolefins, polyamides, polyesters such as polyethylene teraphthalate and thermoplastic polyurethane elastomers. Many of these materials can be used to make melt blown fabrics having suitable tensile strength and fabric properties, for example, used as wipes for various purposes. After the fabric has been used, the wipe or other article is generally disposed of in a landfill.
Because of the desirability of having the capability of recycling the fibers which make up fabrics such as those used as wipes, thus saving the resources used in forming the fabrics and in reduction of volume of materials placed in landfills, a need has existed for improved binder compositions. Specifically, a binder that would retain strength and integrity during the course of intended use which could readily be dissolved for reuse of the components would be highly desirable.
As already noted, hot melt compositions based on polymers such as polyolefins, polyamides, polyurethanes or polyesters have been used to produce nonwoven fabrics by melt blown spray procedures. In such cases, the binder polymer is used to bind fibers which may be formed of synthetic materials or natural materials such as cellulosic fibers. Such fabrics are useful for wipes used in various ways. Currently used binders do not facilitate recycling or easy disposal of used fabrics, which thus generally end up in a landfill.
A need has, thus, existed for improved binders for melt blown fabrics which would have acceptable tensile strength yet could be disposed of by easy disintegration into the component parts.